1. Field of the Invention
This invention is concerned with a lens driving device which drives a group of lenses by an electric power drive in optical equipment, especially camera lenses.
2. Description of Related Art
In the recent years, there has been developed an increasing number of still cameras, such as compact cameras with a so called lens shutter system, which are equipped with a motor-driven power zoom lens for zooming.
When taking pictures using a camera with such a power zoom lens, there is a time when the user wants to zoom the subject at a certain focal length quickly, for instance in such a case described below. When shooting at the moment a moving subject passes through a certain point, the photographer determines the shooting position beforehand, directs the camera to the specific point, determines a desired composition by zooming, brings the point into focus by the automatic focusing and waits. In this situation, when the subject does not comes into the specific position, the photographer may zoom in and out, or direct the camera to other subjects. When the composition is different from the desired one such as this, it may not be possible to bring the focus back to the desired focal length by the time the subject comes to the specific position.